Boat trailer



FIG. 1 is a side elevational view of a boat trailer showing my new design, it being understood that the broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and

FIG. 7 is a side elevational view opposite to that shown in FIG. 4. 

The ornamental design for a boat trailer, as shown and described. 